THE tragedy was witnessed by millions of Americans who watched on live television for the Challenger to make history.
But why did the space shuttle break apart, and how many people died? Here’s what we know about the 73-second doomed flight.
Getty – Contributor Space Shuttle Challenger exploded after just 73 seconds in the air
When was the Challenger disaster?
The NASA shuttle orbiter broke apart just 73 seconds into its flight on January 28, 1986, at 11.39am local time.
It was the tenth flight the Space Shuttle Challenger had taken.
The spacecraft fell apart off the coast of Cape Canaveral in Florida.
The crew compartment ascended to an altitude of 12.3 miles before free-falling into the Atlantic Ocean.
Why did the space shuttle break apart?
The vehicle began disintegrating after a join in its right solid rocket booster (SRB) failed at liftoff.
This was down to the unusually cold weather that the O-ring seals were not designed to handle.
As the shuttle ascended, one of the seals opened enough to allow a plume of exhaust to leak out.
Hot gases than bathed the cold external tank full of liquid oxygen and hydrogen, until the tank ruptured.
Aerodynamic forces then broke up the orbiter.
Getty Images The astronauts and payload specialists who lost their lives in the tragedy
How many people died?
All seven crew members died when the space craft exploded.
They were: challenger commander Dick Scobee, pilot Michael Smith and mission specialists Judy Resnik, Ronald McNair and Ellison Onizuka.
Payload specialist Gregory Jarvis and high school teacher Christa McAuliffe – who was set to become the first teacher in space – were also killed in the tragedy.
McAuliffe had been selected from 11,000 applicants to NASA’s Teacher in Space Project, which aimed to remind Americans the important role teachers played in their country by sending an educator up into space.